In August, NASA launched the Parker Solar Probe, a mission to get up close and personal with the Sun. Between October 31 and November 11, the probe made its first flyby through the outer atmosphere of the star. We’re just now getting data from that close encounter, including the probe’s first glamour shots of the sun, which were recently shared by the mission’s scientists at the American Geophysical Union annual conference.
Jonathan Amos at the BBC explains that the fiery image was captured on November 8 from about 16.9 million miles above the star. In the photo, plasma—the energetic gas that makes up much of the sun—can be seen flowing from the sun’s surface while Mercury, which appears as a bright dot, passes by. The snapshot was taken by the Wide-field Imager for Solar Probe, a telescope designed to take images of the sun’s corona and inner heliosphere as well as solar wind and other features.
The image and data that accompanies it represent a huge step forward.
“Heliophysicists have been waiting more than 60 years for a mission like this to be possible,” Nicola Fox, director of the Heliophysics Division at NASA says in a press release. “The solar mysteries we want to solve are waiting in the corona.”
This first drip of data is just a tiny taste of the information researchers hope to get from the probe. Ultimately, Fox tells Doris Elin Salazar at Space.com, the team wants the craft to sample particles, magnetic and electric fields in the corona to understand its properties.
While it may seem logical for the sun to get hotter as you get closer to its center, that’s not the case. The corona, or outer atmosphere, is much hotter than the photosphere, what we might call the sun’s surface. While the photosphere reaches about 6,000 degrees Celsius, the corona can reach a few million degrees. The Parker team hopes the probe will help them figure out exactly why this temperature inversion takes place.
“We need to go into this region to be able to sample the new plasma, the newly formed material, to be able to see what processes, what physics, is taking place in there,” Fox tells Amos. “We want to understand why there is this temperature inversion, as in - you walk away from a hot star and the atmosphere gets hotter not colder as you would expect.”
The sun-kissing probe also has two other major missions. First, it will measure solar wind, which are outflows of charged particles that whip off the sun and interact with the planets and other objects in the solar system. The big question is how solar wind is able to stream off the sun so quickly, moving at up to one million miles per hour. The team will also study solar energetic particles, which are ejected from the at half the speed of light.
Of course, answering those questions means getting specialized instruments as close to the sun as possible. The probe is already as close to the sun as a human-made device has even gotten, and will eventually get even closer. Salazar at Space.com reports that Parker will conduct 24 orbits around the sun including its closest flyby which will bring it just 3.7 million miles from the surface, about one-eighth the distance between Mercury and the sun, which will send back some truly incredible data.
“We don’t know what to expect so close to the Sun until we get the data, and we’ll probably see some new phenomena,” Nour Raouafi, project scientist at the Johns Hopkins University Applied Physics Lab says in the release. “Parker is an exploration mission—the potential for new discoveries is huge.”